Switch operator



May 21, 1968 M. G. ZAVERTNIK ETAL 3,384,727

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QTToRNEv/ United States Patent O 3,384,727 SWITCH OPERATR Marshall G. Zavcrtnik, Manchester, Mo., Charles C. Montgomery, East St. Louis, Ill., and John W. Buser, St. Louis, and Charles E. Williams, Rock Hill, M0., assignors to Killark Electric Manufacturing Company, St. Louis, Mo., a corporation of Missouri Filed Feb. 28, 1966, Ser. No. 530,532 2 Claims. (Cl. 200-159) ABSTRACT F THE DISCLOSURE A switch operator for use in locations requiring protection against hazardous flame and/ or hazardous dust and/ or weatherproof protection. A rotatable, depressible actuator for selectively operating switch contacts. A lever to selectively lock the actuator in or out of operating position.

Brief description of the invention In general, this switch operator comprises a body having an operating end withs parts arranged for manual operation, and a switch actuating end with parts arranged to selectively depress a buton or butons or parts of a switch or a gang of switches. The parts at the actuating end are positioned between frame members that can be attached to the switch body. The body is threaded through a wall separating the exterior hazardous location from the interior of an explosion proof box.

The general object of this invention is to provide a switch operator of the foregoing kind that can operate selective buttons of a switch and that protects against hazardous dust and hazardous ame and is weatherproof.

Another object of the invention is to provide a hazardous location switch operator having lockout means to lock the operator in a predetermined position.

Another object of the invention is to provide a switch operator as described that is easily assembled in the Iield by unskilled persons.

Other objects and advantages will be apparent to those skilled in the art.

In the drawings:

FIGURE l is a top plan view of the switch operator with the lockout lever in withdrawn position;

FIGURE 2 is a top plan view of the switch operator with the lockout lever in locking position;

FIGURE 3 is a side elevation view of the switch operator of FIGURE l;

FIGURE 4 is a side elevation view of the switch operator of FIGURE l, as viewed from the right side of FIGURE 3;

FIGURE 5 is a view in section taken along the line 5 5 of FIGURE 3, but showing the lockout lever in lockout position locking the operator knob against depression;

FIGURE 6 is an enlarged view in section taken along the line 6 6 of FIGURE 3;

FIGURE 7 is a fragmentary enlarged view in section taken along the line 7 7 of FIGURE 3;

FIGURE 8 is an enlarged view in section taken along the line 8 8 of FIGURE l;

FIGURE 9 is a fragmentary view in section taken along the line 9 9 of FIGURE 8;

FIGURE 10 is a side elevation view of the manual operating knob;

FIGURE ll is a side elevation View of the switch operator similar to the view of FIGURE 3, but showing the lockout lever in locking position;

FIGURE l2 is a view in section taken along the line 12 12 of FIGURE 11;

FIGURE 13 is a fragmentary side elevation view of the 3,384,727 Patented May 21, 1968 ICE actuating end of the switch operator, showing the actuator disk rotated to a position to depress one of the switch buttons;

FIGURE l4 is a fragmentary side elevation view similar to that of FIGURE l3 but showing the actuator disk rotated in the opposite direction to depress the other switch button; and

FIGURE 15 is a view in section on an enlarged scale taken along the line 15 15 of FIGURE 14.

Referring now to the drawings, this switch operator has an externally threaded central body 21 with an upper end 22 and a lower end 23. There is a hole 24 in the side of the body 21 near the upper end 22 for a purpose which will be explained. There is also a passage or bore 25 through the body 21 from its upper end 22 to its lower end 23. A pair of lock rings 26 and 27 are threaded onto the body 21.

An actuating end 30 comprises a frame 31 made of non-conductive material, such as Bakelite, and having a rectangular base 32 fastened by countersunk screws 33 to the lower end 23 of the body 21. There is an opening 34 through the center of the base 32 coaxial with the bore 25 and larger in diameter, and a crescent-shaped wall 36 extends downwardly from the plate 32. As FIGURE 6 shows, the wall 36 extends for slightly more than a semicircle and has inwardly extending ends 37 and 38. The frame 31 also has two spaced arms 39 and 40 that extend downwardly from the base 32.

The switch body 42 is fastened to the frame 31 by threading two screws 43 and 44 into the lower ends of the arms 39 and 4t). The switch 42 is a conventional one of the kind having two depressible operating buttons 45 and 46 and having various lugs or terminals 47 for connecting wires (not shown).

As shown particularly in FIGURE 8, a shaft 50 extends through the bore 25 in the body 21 and through the hole 34 in the frame 31. There is a reduced diameter section 51 adjacent the lower end of the shaft 50, and at the extreme lower end, a flat-sided hub 52. A groove 53 is cut in the shaft 50 slightly above the reduced diameter section 51, and a snap ring 54 received within the groove 53 normally bears against the lower end 23 of the body 21.

An actuator disk 57 has a recess 58 in it for 4receiving the hub 52 at the lower end of the shaft 50. The recess 58 is complementary in shape to the shape of the hub 52 so that the actuator disk 57 cannot rotate relative to the shaft 50. The actuator disk 57 is held by a screw 59 to the end of the shaft 50. The actuaor disk 57 is generally crescent-shaped, or slightly more than a semi-circle, with an upwardly extending finger 60 projecting into the area defined by the crescent-shaped wall 36, as shown in FIG- URE 6. A coil spring 61 is wrapped about the shaft section 51 wtih arms 62 and `63 bearing against opposite sides of the finger 60 and of the frame arm 39 and normally biasing the finger 60 to the position shown in FIGURE 6, and the actuator disk 57 to the position there shown.

The upper end 65 of the shaft 50, as shown in FIG- URE 8, has an operating knob 66 secured onto this end 65. The operating knob 66 has a base 67 of slightly smaller diameter than the diameter of the body 21. There is a at-sided iinger extension 68 projecting upwardly from the base 67 to facilitate rotation of the knob 66.

A compression spring 70 surrounds the shaft 5t) and is positioned between the base 67 and the top 24 of the body 21. The compression spring 70 biases the knob 66 and the shaft 50 upwardly until the snapl ring 54 bears against the lower end 23 of the body 21.

Spaced laterally outwardly from the compression spring 70, there are three upwardly extending recesses 71, 72, and 73 in the base 67 of the knob 66 (see FIGURE 9). A pin 75 projects upwardiy from the body 21. The pin 75 and the recesses 71-73 are ali at the same radial distance from the axis of the shaft 50. Ordinarily, the knob 66 can be rotated without interference from the pin 75 when the spring 70 is holding the knob and shaft 5t) in its extreme upper position with the snap ring Se bearing against the lower end 23 of the body 2l, However, the pin 75 is received within one of the recesses 7l, 72, or 73 when the knob `66 and shaft 56 are depressed against the force of the compression spring 70. Because of the pin 75, this depression of the knob and shaft 56 can occur only when the pin is opposite one of the recesses 70-73.

There is a guard '78 having internal threads 7% at the lower end of a central recess Si) by which the guard 78 is threaded onto the upper end of the body 2l. The knob 66 tits freely within the recess 80 of the guard, with the side wall 81 of the guard laterally surrounding the knob 66. A lug 82 extends upwardly from the wall Si and has a hole 83 through it. As shown in FIGURE 5, the guard is locked in place by a setscrew S4 that extends into the recess 24 in the 'body 21 to prevent rotation of the guard relative to the body.

A lockout lever 86 has an arm 87 pivotally fastened to the guard 7S by means of a screw 88, as best seen in FIGURE 8. There is an upwardly extending lug 89 at the outer end of the arm 87 which has a hole 90 through it. A lockin-lockout extension 91 projects inwardly from the arm S7, and there is a slot 92 through the wall 81 of the guard 78 through which the lookin-lockout extension 91 extends, and another slot 93 in a side of the base 67 of the knob 66 into which the lockin-lockout extension projects when the lockout lever 86 is in the position shown in FIGURES 11 and 12. There could be other slots 93 in other positions of the knob to provide different lockin positions. Also in this position of the lockout lever 86, the lugs 82 and 89 are opposite one another, and a padlock 95 (shown in broken lines), can be used to lock the lever 86 in that position. However, the slot 93 is aligned with the slot 92 only when the knob 66 occupies the position shown in FIGURES 1l and 12 and is depressed from the position shown in FIGURE (after pivoting the lockout lever 86 to the position shown in FIGURE 2), depressing both the buttons 45 and 46 of the switch 42. If other slots 93 are provided, other lockin positions of the knob would result. Also, other means for mounting the lockout lever may be used, such as a sliding moment or the like.

This switch operator 20 is easily installed for use. The setscrew 84 is simply loosened or removed and the guard 78 and lock ring 26 are unthreaded from the body 21. Then the body 21 is threaded through an appropriate threaded hole through the side of a wall enclosing a hazardous area so that the actuating end 30 is contained within the hazardous area and the end 22 of the body projects from the other side of the wall. Then the lock rings 26 and 27 are tightened against the opposite sides of the wall, and the guard 78 is replaced. When correctly replaced, the guard will always be properly oriented because the setscrew 84 must be aligned with the recess 24 before it can be tightened, since the setscrew projects into the recess 24. With this proper orientation, the slot 92 in the guard is on the same side of the knob 66 as the slot 93 in the knob when the knob 66, the shaft 5G, and the actuator disk 57 are in their normal positions as biased by the arms 62 and 63 of the spring 61 (see FIGURES 5 and 6). In this position, the actuator disk 57 overlies both the switch buttons 45 and 46 and the recess 72 in the knob 66 overlies the pin 75. Therefore, depression ot the knob 66 depresses the actuator disk S7 against both the switch buttons 4S and 46 moving them through a portion of their stroke and, if locking is desired, the lockout lever 86 can be swung from the position shown in FIG- URE 1 to the position shown in FIGURE 2 in which the lockout extension 91 projects into the slot 93 and prevents the compression spring 70 from returning the knob 66 and the disk 57 to the elevated position.

When the knob 66 is released from the lockout lever S6 by swinging the lockout lever to the position shown in FIGURE 1, the spring 70 again raises the shaft 50 until the snap ring S3 stops against the lower end of the body 2l. Then to depress only the switch button 45, the knob 66 is rotated in a counterclockwise direction as viewed in FIGURE 2 and the knob 66 is depressed. Depression of the knob and the shaft 5G depresses the actuator disk 57 against the button 45 but, in the rotated position shown in FIGURE 13, the crescent-shaped actuator disk 57 misses the button 46. The knob 66 can be depressed when it is rotated to the proper position because the recess 73 is then positioned immediately above the pin 75. When the knob is released, the compression spring 76 raises it, and the torsion spring 61 returns the actuator disk 57, and the knob 66, to the normal position shown in FIG- URE 6.

Rotation of the knob 66 in a clockwise direction as viewed in FIGURE 2, enables depression of the knob 66, the shaft 5i) and the actuator disk 57 to depress only the button 46, missing the button 4S. In this position of the knob 66, the recess 71 must 'be positioned immediately above the pin 75.

To lock the switch operator against operating the switch, the lockout lever 86 is swung to the position shown in FIGURES 4 and 5 and padlocked in place. In this position, the lug 9i extends under the base 67 of the knob 66 and prevents depression of the knob, irrespective of the position to which the knob is turned.

Various changes and modifications may be made within the purview of this invention as will be readily apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as dened by the claims appended hereto.

What is claimed is:

1. A switch operator to operate the operating means of a switch located in a hazardous location of the kind which is isolated by a wall, the switch having at least two buttons for selective depression by the switch operator, comprising an externally threaded cylindrical body for being threaded into a hole through the wall, a bore through the body, a shaft rotatably supported within the bore, a knob afhxed to one end of the shaft, an actuator disk atiixed to the other end of the shaft, the shaft, the knob, the actuator disk being slidable in a direction away from contact with the switch operating means and alternately toward the switch operating means to move the actuator disk into contact with the swich operating means, the actuator disk having portions overlying both buttons in one rotative position of the disk, a portion overlying one button in another rotative position of the disk, and a portion overlying the other button in still another rotative position of the disk, means for preventing depression of the actuator disk against the buttons unless the actuator disk is in one of the three aforesaid positions, a spring to bias the actuator disk to the rst-named rotative position, means for biasing the shaft, the knob and the actuator disk in the said direction away from contact with the switch operating means, a guard threaded onto the body adjacent the knob, a lockout lever supported by the guard, a slot in the knob, a slot through the guard, and a plate extension on the lockout lever for moving into the slot when the lockout lever is moved to a lockout position and the knob is out of contact with the switch operating means, a slot in the knob for receiving the plate extension when the knob is depressed in a predetermined rotative position, the guard having an opening through it large enough to permit free passage'of the knob, a recess in the body, and a setscrew in the guard for extending into the recess when the guard is properly oriented.

2. The switch operator of claim 1 including a frame attached to the body and having arms extending alongside the actuator disk, and means to attach the frame arms to the body of the switch to be operated,

(References on following page) References Cited UNITED STATES PATENTS 3/ 1945 Robbins 200-159 6/1954 Ballou 20G-159 2/1956 Jenkins et al. 200-159 7/1967 Farina 200--167 6 FOREIGN PATENTS 7/1964 Canada. 8/ 1961 Great Britain.

5 ROBERT K. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner. 

